The present invention relates to a tool for installing fasteners, and more particularly to a tool for installing a particular fastener that is used to join layers of roofing material.
The development of a fastener for joining layers of insulation to a light weight deck or for joining two layers of insulation, such as the fastener disclosed in this application and the fastener disclosed in the above mentioned application, required the development of a special tool for the installation of fasteners of this type.
The fasteners include an externally threaded elongated member terminating in a tip and an internal channel which may or may not also be threaded and which contains a flexible barb and its associated plunger member. Thus, it is necessary that a tool for installing fasteners of this type be capable of providing rotational motion to the fastener itself so that it may be screwed into the material. The tool must also be capable of engaging the plunger and causing its downward movement so that the barb may be forced from the internal channel in the fastener.
The fasteners themselves may take on two different embodiments. The fastener may be of the type shown in the above mentioned patent application wherein the plunger is merely slidably contained within the channel or the fastener may be of the type as disclosed in this application in which the channel itself is threaded and the plunger includes threads that mesh with the threads of the channel so that rotational motion of the plunger results in longitudinal motion of the plunger toward the tip of the fastener. It is also possible to utilize a non-threaded channel containing a self tapping plunger assembly that upon rotating accomplishes the same results.
Therefore, in order for the tool to be operable with both types of fasteners it is necessary for the tool to be capable not only of imparting a downward motion to a slidable plunger but also be capable of imparting a rotational motion to a threaded or self tapping plunger.
Tools such as that shown in U.S. Pat. No. 3,479,714 to Allsop provide rotational motion to a nut and then deliver an impact to the nut. While impact wrenches such as the Blue Point AT300A power impact wrench manufactured by Snap-On Tools merely provide rotational motion to the fastener.
It is the object of the present invention to provide a tool for installing fasteners of the type discussed above which will impart a rotational motion to the fastener and also provide either an impact to the plunger within the fastener or a rotational motion to the plunger depending on the type of fastener being used.